Components

Under the Hood

The Cropping System Model (CSM) released with DSSAT v4.0 represented a major departure from DSSAT v3.5 and earlier released versions of DSSAT. This does not refer to the function but more to design. The computer source code for the model has been restructured into a modular format in which components separate along scientific discipline lines and are structured to allow easy replacement or addition of modules. CSM now incorporates all crops as modules using a single soil model and a single weather module. The new cropping system model now contains models of 28 crops derived from the old DSSAT CROPGRO and CERES crop growth models.

Major Modules

A SOM–residue module from the CENTURY model was incorporated in the DSSAT crop simulation models, and a residue layer was added on top of the soil. Modifications were also made in the senescence module of CROPGRO, a model within DSSAT, so that senesced material is now added daily to the soil. By incorporating the CENTURY SOM–residue module, DSSAT crop simulation models have become more suitable for simulating low-input systems and conducting long-term sustainability analyses.

Weather module – Reads or generates daily weather data

Soil-Plant-Atmosphere module – Deals with competition for light and water among the soil, plants, and atmosphere